DEGREES OF FREEDOM IN MULTICELL WIRELESS SYSTEMS WITH FULL-DUPLEX BASE STATIONS USING INTERFERENCE ALIGNMENT AND METHODS FOR ENABLING FULL-DUPLEX WITH HALF DUPLEX CLIENTS

• US 20150223173A1
• Filed: 12/04/2014
• Published: 08/06/2015
• Est. Priority Date: 12/04/2013
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Laboratories America Inc (NEC Corporation)
• Inventors: Khojastepour, Mohammad, SUNDARESAN, KARTHIKEYAN, Rangarajan, Sampath, Chai, Eugene
• Granted Patent: US 9,736,785 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0421 utilizing implicit feedback, e.g. steered pilot signals
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/16 Half-duplex systems; Simplex/duplex switching; Transmission of break signals non-automatically inverting the direction of transmission
• CPC Class Codes: H04W 52/14 Separate analysis of uplink or downlink
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

An interference alignment system for communication structures that includes a single cell channel comprising an access point node, and a full bipartite interference channel (FBIC) configuration of a plurality of receiving nodes and a plurality of transmitting nodes. Each receiving node sees an interfering signal from all transmitting nodes. The access point node of the single cell channel provides a single node having downlink channels to all receiving nodes in the FBIC, and all of the uplink channels from the FBIC are to the single access point node to the single cell channel.

Claims

1-20. -20. (canceled)

21. A communications method implemented in a communications node working in a full duplex mode and used in a wireless communications system, the communications method comprising:

receiving, from a plurality of transmitting nodes, first communications data;

simultaneously with the receiving, transmitting, to a plurality of receiving nodes, second communications data; and

deciding at least part of transmit precoders and receive filters for alignment of interference from the plurality of transmitting nodes to the plurality of receiving nodes.

22. The communications method as in claim 21,

wherein each of the plurality of receiving nodes and the plurality of transmitting nodes works in a half duplex mode.

23. The communications method as in claim 21,

wherein the communications node comprises an access node or a base station, and each of the plurality of transmitting nodes and the plurality of receiving nodes comprises a mobile device, a client device, or a user equipment.

24. The communications method as in claim 21,

wherein the alignment of interference is performed in a full bipartite interference channel (FBIC).

25. The communications method as in claim 21,

wherein the transmit precoders and the receive filters are used for precoding and filtering, respectively, in at least one of time domain, subcarrier domain, and space domain.

26. The communications method as in claim 21,

wherein the number of the plurality of receiving nodes is limited up to 2, and the number of the plurality of transmitting nodes is limited up to 2.

27. The communications method as in claim 21,

wherein the communications node includes N antennas, the plurality of transmitting nodes use N/2 out of N degrees of freedom, and the plurality of receiving nodes use N/2 out of N degrees of freedom.

28. The communications method as in claim 21,

wherein the deciding is performed in a distributed form.

29. The communications method as in claim 21,

wherein the plurality of receiving nodes receive an uplink-downlink interference (UDI) signal from the plurality of transmitting nodes.

30. A communications method implemented in a receiving node used in a wireless communications system, the communications method comprising:

estimating a wireless channel between the receiving node and a transmitting node;

deciding a receive filter for performing alignment of interference from the transmitting node to the receiving node;

receiving, from a communications node working in a full duplex mode, communications data; and

applying the receive filter to the communications data.

31. The communications method as in claim 30,

wherein the receiving node has at least one dimension for data reception from the communications node.

32. The communications method as in claim 30,

wherein each of the receiving node and the transmitting node works in a half duplex mode.

33. The communications method as in claim 30,

wherein the communications node comprises an access node or a base station, and each of the transmitting node and the receiving node comprises a mobile device, a client device, or a user equipment.

34. The communications method as in claim 30,

wherein the alignment of interference is performed in a full bipartite interference channel (FBIC).

35. The communications method as in claim 30,

wherein the receive filter is used for filtering in at least one of time domain, subcarrier domain, and space domain.

36. A communications method implemented in a transmitting node used in a wireless communications system, the communications method comprising:

estimating a wireless channel between a receiving node and the transmitting node;

deciding a transmit precoder for alignment of interference at the receiving node;

transmitting, to a communications node working in a full duplex mode, communications data; and

applying the transmit precoder to the communications data.

37. The communications method as in claim 36,

wherein each of the receiving node and the transmitting node works in a half duplex mode.

38. The communications method as in claim 36,

wherein the communications node comprises an access node or a base station, and each of the transmitting node and the receiving node comprises a mobile device, a client device, or a user equipment.

39. The communications method as in claim 36,

wherein the alignment of interference is performed in a full bipartite interference channel (FBIC).

40. The communications method as in claim 36,

wherein the transmit precoder is used for precoding in at least one of time domain, subcarrier domain, and space domain.